Fan in case should blow suck

[EzCo]

I have several cases and they are all different. None of my computers are overclocked but I was thinking of replacing the and/or adding fans to the case to make it more quiet. Should the fan in the powersupply be blowing air into the box or sucking it out (my two ATX:es are different)? What if I add another fan in the front of the case? should it suck or blow? Is it better to add a fan in front of the case instead of another one in the back when adding another one?

Can anyone explain this or maybe supply me with a guide or good webpage that explains all this!

Thanks!

 

[cakecake]

Not many guides or web pages. And not a single comprehensive, universal one that I know of.

Be careful when replacing a PSU fan or opening it up in any way. You could be electrocuted. Don't even touch the heatsinks inside the PSU. Those often are connected direct to live lines. You want the PSU to suck air to the outside of the case. This draws hot air away from the processor. Follow these guidelines:

1) if you do not have any form of exhaust fan (a fan that pushes air out the back), then that's more important than anything else. Generally a power supply with a bottom intake fan (2-fan PSU) is considered an exhaust fan. If your PSU only has 1 fan shooting out the back then that is not an exhaust fan.
2) if you have an exhaust fan but no fans in front sucking air in then get fans sucking air in before you get a second exhaust fan.
3) Be careful that any fans you replace don't add too much noise.

1° of separation between my monopoly and yours. That's business with .NET<P ID="edit"><FONT SIZE=-1><EM>Edited by cakecake on 07/30/02 10:31 PM.</EM></FONT></P>

 

[EzCo]

I've read somewhere som general tips how to more or less discharge the PSU but can't remember where. Something about disconnecting it and turning the powerbutton on and off for several times and leave it disconnected for a while and after that it's pretty safe to open it up. True?

Since I don't want to spend too much money on a new ultrasilent PSU when I already have a couple of silent fans just laying around.

 

[cakecake]

I'd imagine there would be some way of discharging it, yes. But just be very careful. If you are unsure, it's better to not get electrocuted (trust me it don't feel so good =P).

1° of separation between my monopoly and yours. That's business with .NET<P ID="edit"><FONT SIZE=-1><EM>Edited by cakecake on 07/30/02 10:29 PM.</EM></FONT></P>

 

[DaveGOD]

turn power off from the mains but leave the power cable in, then hold the power button down for 10 seconds. This will not however completely discharge it; it is only a "if you REALLY MUST then might as well". There shouldnt be any need to open your PSU unless the fan fails, i really suggest you do not do it

PSU fan sucks air out of the psu box, theyre usually tiddly things and barely make much impact on case temps other than removing the heat generated by psu.



<A HREF="http://www.anandtech.com/mysystemrig.html?id=14094" target="_new">My Rig</A>

 

[cakecake]

Do you mean remove the big black power cord and then hold down the power button for 10 seconds?

1° of separation between my monopoly and yours. That's business with .NET

 

[DaveGOD]

not entirely sure with non-uk plugs: we have power switch on the wallsocket and a third pin on plugs for earthing, so you leave the power cable plugged into the psu (and the wallsocket, though the switch is off) whilst holding the button, presumably this drains the capacitors whilst not having enough power to boot the pc (though some may have a go at starting up). If the cable is not plugged in both ends, theres no connection hence there will not be any drain. Not exactly 100% on this, just what ive read about and seems to make some sense. Like i said though, i'd hardly then consider my psu to be safe to poke about with a fork whilst sitting in the bath

<A HREF="http://www.anandtech.com/mysystemrig.html?id=14094" target="_new">My Rig</A>

 

[cakecake]

Here's what I did, using the American version of the power plug. First I removed the power cord from the back of the PSU, the lifeline for my whole computer system. Then I pressed and held the power button down for about 30 seconds. When the power button was depressed without the power cord attached, the fans spun up momentarily; this must have been the release of energy. Finally I turned the switch in back from I to O (on to off). After that I did my modding/adjustments and then put it back into my computer and I'm using it right now with no problems at all.

I still was very careful when I did my PSU modding to the point where I do not believe my skin ever came in contact with any capacitors, heatsinks, or other electrically conductive part of the power supply. Still, there may have been one or two times when I did touch a galvanic part, but I believe what I did earlier discharged it sufficiently enough.

Someday I'd like to water cool a PSU some time. I saw a documentation someone did on modding their own 550W Enermax PSU to cool down its MOSFETs. But even after extensive searching I can't seem to find it anymore. But imagine a computer system where the there are only two sources of noise: a single radiator fan and a hard drive!

1° of separation between my monopoly and yours. That's business with .NET